A new real-time, noninvasive optical tool could help surgeons avoid hitting a nerve.

It can be difficult for surgeons to distinguish nerves from other tissues during operations, and sometimes they accidentally damage a nerve. The new tool may help reduce these accidents by clearly illuminating the nerves.

The technology uses a technique called collimated polarized light imaging, or CPLi, to make nerves stand out from other tissues. When a beam of polarized light passes through a nerve, the nerve tissue’s unique structure reflects the light in a particular way. Surgeons can illuminate nerves by rotating the light’s polarization, forgoing the need for fluorescent markers or physical contact with the nerve.

In a recent paper in the journal Biomedical Optics Express, researchers reported that a surgeon using CPLi technology was able to correctly identify nerves in a human cadaver hand 100 percent of the time. Another surgeon using traditional visual inspection had an accuracy rate of 77 percent.

Preliminary CPLi identifications of nerves in a live patient during a procedure were also promising.

Overall, the results show that CPLi allows surgeons to spot human nerves in real-time and with greater reliability than by visual inspection alone. This technique could help surgeons identify nerves during surgery and minimize accidental nerve damage.